Interesting. I just read this on people.com in an article about Case Anthony. It's talking about video of her after she watched a news report of remains being found that were later revealed as Caylee's:
"In court on Wednesday, a media organization argued for the release of a jailhouse video of Casey watching TV news reports saying police found remains, which turned out to be her missing daughter, 2-year-old Caylee.
According to detectives, Anthony doubled over and hyperventilated before asking for a sedative in the video."
This reminds me of how SM seemed to be hyperventilating in his interview footage after he was told that a body had been discovered.
Read full article about Anthony here:
http://www.people.com/people/article/0,,20532760,00.html